Display screen or portion thereof with transitional graphical user interface



FIG. 1 is the first image in a sequence for a display screen or portionthereof with transitional graphical user interface showing our newdesign;

FIG. 2 is the second image thereof;

FIG. 3 is the third image thereof;

FIG. 4 is the fourth image thereof;

FIG. 5 is the fifth image thereof;

FIG. 6 is the sixth image thereof;

FIG. 7 is the seventh image thereof;

FIG. 8 is the eighth image thereof;

FIG. 9 is the ninth image thereof; and,

FIG. 10 is the tenth image thereof.

The appearance of the animated user interface sequentially transitionsbetween the images shown in FIGS. 1-10. The process or period in whichone image transitions to another forms no part of the claimed design.The broken line showing of the alphanumeric characters, symbols, anddisplay screen in the Figures is for environmental purposes only andforms no part of the claimed design.

CLAIM The ornamental design for a display screen or portion thereof withtransitional graphical user interface, as shown and described.